Abstract 2R,3R-Dihydromyricetin (DMY) is a natural flavonoid that has versatile biological activities. However, due to its poor water solubility and low chemical stability, its applications in food and pharmaceutical fields remain limited. Inclusion of DMY with cyclodextrins (CDs) has been shown to improve the solubility and stability of DMY, whereas the mechanism for the inclusion has not been elucidated. This study investigated the characteristic and mechanism for inclusion of DMY with CDs, and evaluated the effects of complexation on antioxidant and lipid-lowering activities of DMY. Phase solubility studies revealed that the solubility of DMY was significantly improved in the presence of natural (α-, β-, γ-) CDs and their derivatives, namely hydroxypropyl-β-cyclodextrin (HP-β-CD) and (2,6-di-O-methyl)-β-cyclodextrin (DM-β-CD), by forming 1:1 stoichiometric inclusion complexes. Particularly, the complexes of DMY with HP-β-CD and DM-β-CD were prepared and characterized by FT-IR, PXRD, DSC, SEM and NMR analysis. Furthermore, the possible inclusion configuration was verified by molecular docking, which indicated that B-ring of DMY was fully embedded in the cavity of CDs while C-ring and A-ring were partly included, through non-covalent interaction such as hydrogen bonding. The results also showed that inclusion of DMY with HP-β-CD or DM-β-CD enhanced the radical scavenging capacity of DMY and maintained its lipid-lowering effect in hyperlipidemia zebrafish model.

中文翻译：

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深入了解 2R,3R-二氢杨梅素与环糊精的结合机制以及络合对抗氧化和降脂活性的影响

摘要 2R,3R-二氢杨梅素（DMY）是一种具有多种生物活性的天然黄酮类化合物。然而，由于其水溶性差和化学稳定性低，其在食品和制药领域的应用仍然受到限制。已证明将 DMY 与环糊精 (CD) 包含在一起可以提高 DMY 的溶解性和稳定性，但尚未阐明包含的机制。本研究调查了 DMY 与 CDs 的结合特性和机制，并评估了络合对 DMY 抗氧化和降脂活性的影响。相溶解度研究表明，在天然（α-、β-、γ-）CDs 及其衍生物，即羟丙基-β-环糊精（HP-β-CD）和（2,6 -di-O-methyl)-β-环糊精 (DM-β-CD)，通过形成 1: 1 化学计量包合物。特别地，制备了DMY与HP-β-CD和DM-β-CD的配合物，并通过FT-IR、PXRD、DSC、SEM和NMR分析对其进行了表征。此外，通过分子对接验证了可能的包含构型，这表明DMY的B环完全嵌入CDs的腔中，而C环和A环则部分包含，通过非共价相互作用，如氢键。结果还表明，在高脂血症斑马鱼模型中，DMY与HP-β-CD或DM-β-CD的结合增强了DMY的自由基清除能力并保持其降脂作用。通过分子对接验证了可能的包含构型，这表明DMY的B环完全嵌入CD的腔中，而C环和A环则部分包含，通过非共价相互作用，如氢键。结果还表明，在高脂血症斑马鱼模型中，DMY与HP-β-CD或DM-β-CD的结合增强了DMY的自由基清除能力并保持其降脂作用。通过分子对接验证了可能的包含构型，这表明DMY的B环完全嵌入CD的腔中，而C环和A环则部分包含，通过非共价相互作用，如氢键。结果还表明，在高脂血症斑马鱼模型中，DMY与HP-β-CD或DM-β-CD的结合增强了DMY的自由基清除能力并保持其降脂作用。